A while back I wrote an article about memes--how they're created and how they're spread. I used iCryptex.com as a case study because it was small-scale and I had all of the necessary data. It's been published on One Degree, a Canadian marketing site:
The Internet is the natural habitat for memes. Why? Because the Web has evolved into the world’s biggest, fastest information exchange. Concepts can emerge, evolve, permeate and perish in days or weeks. The growing popularity of weblogs, online diaries and other frequently-updated sites combined with traditional communication mediums like email and instant-messaging means that a compelling idea can reach hundreds of thousands of people within hours.

Mostly I was pleased with the diagram I created to illustrate the spread of a meme. It's not exactly Tufte-proof, but it's very pretty. You can also digg this, if you're so inclined.